One Fing . The ST isnt LIGHTER than the thinggo 40 , you could move the .46 BACK ! for balance .
SHORTENING the Prop Nut thing , so it only goes say into the FRONT Half Depth , keeps the props ' multi Fit . So still useable on other engines . Allowing the shank on the ST is 7 m.m. ,
Easiest way ( that ) is often a tenth the hassel ! .
Youd need to drill your 1/4 spacer 7 m.m. bore . FIT ALL THE BITS UP , see if there how much thread protuding , and cut Extn. type prop nut for sufficent engagement , say 7 threads min. With it washer accounted for.
Or Try That , and if its no good , whack right into it . When I have , I knok out the nut plates , Wash with thinner above bearers & holes , tape or fit flat wood held with wedges , pour aryldite into the oldbolt holes
and a skin of it across the dressed / block sanded / or Filed Clean & washed - motor mount face .
If Ive a pice of alloy plate the right width , thatll drop in . Maybe flat it all off with good epoxie , drop the plate in , mask edges to retain glue . then Clamp plate lightly . SO THE NEW FACES ARE ALREADY TRUE.
Or just dress the suckers after the stuffs set or kicked off . Theres some give till its cured . So the Clamped ( release agented ) plate can be a late fit . After kicked off- before fully cured .
I use say 1/16 steel with 1/8 N F nuts wider & longer on a ' re-do ' like 1 1/2 x 5/16 , or 2 x 3/8 if theres room . Carefully , Pilot Drill the new bolt holes . If there not in clean wood . A pilot templates essential
as they tend to wander .
So theres say three stages , remove fittings - Thorougly clean up & degrease - reform / reface mounts - redrill & refit for new set up . Contract seems to have escaletd . That Makes FOUR . In for a bit of effort.
A trimmed fancy prop nut'd be a tenth the effort .
The Alumn Brodak Spinner Nuts , go through the FRONT WASHER , for max thread engagement . a steel one done like that would a be a the beast , eh .